Method of radially corrugating sheet metal.



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v A. w. LIVlN T METHOD OF RADlALLY CORR. HEET METAL.

APPLLCATHIN FILED, l4.

WITN ESSES: INVENTOR A. w. LILVINGSTON. METHOD OF RADIALLY CORRUGAT ING SHEET METAL. APPLICATION FILED MAY 20, I914.-

ANDREW w. LIVINGSTON, or OAKLAN CALIFORNIA, AssIGNon. o STANDARD STEEL WHEEL AND TIRE ARMOB. COMPANY, or oAKLANI), oALIFoRNIA, -A conronATIoN or ARIZONA.

To all whom i may concern .5

Be it known that I, ANDREW LIVING- sToN, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented new and useful Improvements in Methods of Radially Corrugating Sheet Metal, of which the following is a specification.

This invention relates to a method of making seamless, radially-corrugated metal sheets, plates or disks, in which the corrugations are of. considerable depth, and it pertains especially to the manufacture of wheels and disk spoke constructions of the character shown and described in my Patent #1,065,537, dated June 24, 1913. In the wheel shown and described-in said patent,

I employ a spoke structure, provided with radial corrugations or indented ribs, the convolutions forming the corrugations being of substantially thesame depth-from the center to the periphery of the spoke structure, and it was in my efiort to evolve a sat- I isfactory method of commercially manufacturing such a spoke construction'that led to the present invention.

The invention consists of the parts and the construction and combination of parts, as hereinafter fully described and claimed, having reference to the accompanying drawings, in which Figure 1 is a view of the wheel disk blank. Fig. 2 is a view of the corrugated disk. Fig. 3 is a view of the first operation of. corrugating. Fig, 4 is a view of the second operation of corrugating. Fig. 5 is an enlarged detail projected section of a disk betweenthe eye and periphery. Fig. 6 is an enlarged detflit projected section of the eye of. the dis of the corrugating dies. Fig. 8 is an enlarged detail cross section of corrugating dies in position to form corrugation. Fig. 9 is an enlargedvdetail section of corrugating dies in first operation. Fig. 10 is an en-. larged detail cross section of corrugating dies in second operation.

A represents a corrugated sheet, made according to the invention, having a central hole a, and in which sheet the radial corrugations are of substantially the same depth fromcenter tothe periphery of the sheet,

the bottoms 2 of the corrugations or inden tationsbeing"substantially flat and gradu- Specification of Letters Patent.

the spoke ribs.

Fig. 7 is a detail longitudinal section METHOD or nADIAL YconRUGATING SHEET METAL.

ally flared from the center to the periphery. Substantially the entire bottom of each corrugation onone side of the sheet lies in the Patented Nov. 2, 1915.

Application filed May 20, 1914. Serial No. 839,730.

same plane, and substantially the entire part of every bottomon the other side of the sheet lies'in another plane; both planes be- Ing parallel with each other. Also, the corrugations or indentations extend from the center of the wheel to the periphery, so that when the, corrugated disk is slipped on td a hub, 1t is given a rigid support against side- WIse rocking motion; similarly, a rim has a maximum footing support on the ends of gations extend radially and are substantially straight except where they lead at each side into. the body of the sheet by uniform curves 4 at the angles formed with the alternate bottoms. Owing to the depth of the corrugations in this construction, it has been found aphysical impossibility to stamp such a sheet at one operation, or in fact to make more than a single corrugation or spoke ,at one operation. The chief reason for the difficulty lies in the fact that the finished product, indicated in Fig. 2, is at least six inches smaller in diameter than theblank illustrated in Fig. 1, that it is formed from. If

two opposite spokes were attempted to be formed in one operation, the center or pitch of any shape, square, circular. orotherwise,

and make a hole a in the center of the blank sufliciently large to allow for shrinkage. For instance in making a 24 inch'wheel-With twelve corrugations each 1%; inchesdeep and desiring to allow for a six inch shrinkage, so that the center hole a shall fit a 3 inch huh, I would make the center hole a originall 9% inches in diameter. I then form on t e periphery of the blank a series of The walls 3 of the corruequall spaced marks or notches 7, correspending to the number of spokes or corrugations to be formed and in the radius of each notch 7, and adjacent to hole a I make a small perforation 8; the purpose of the notch 7 and perforation 8 being to provide guide means for centering the sheet in stamping it in the press. 7

Any suitable form' of press may be employed to stamp the sheet, and having dies as illustrated and indicated at B in the drawings; the essential feature being the male and female die members 910 shaped to stamp a single corrugation of desired depth and fiare, and provided with a center pin 11 to fit a perforation 8 in the sheet and a guide boss 12 to fit the notch 7. I then proceed to make one corruga-Q tion or spoke rib at a time until I have all the spoke corrugations struck up, as shown in Fig. 2. The depth of the corruga tions may be varied at will by simply changing the thickness of the dies. By this process it is possible to get any depth desired and at the same time the shape of the spoke or corrugation can be made to suit the fancy or needs of the operator. As each spoke is stamped by the press the sheet warps and dishes until the last is struck, when the sheet assumes again nearly a true plane, yet it is usual to place the finally corrugated sheet made by dies B, in a second press under a master die, and give, it a final stamping at a single operation. I

It is obvious that this process can be used for other purposes than for stamping circular blanks, as any irregular square or oblong would respond to the same treatment; the vital point being the hole in the center of the blank. It is the hole a; that allows the steel of the plate to shrink toward the center, and it is the making of the one rib at a time thtat allows shrinkage to take place for each r1 B making the central hole a large enough to allow for shrinkage during the stamping process, and stamping the corrugations singly, I am enabled to make the corrugations of any desired depth and to extend them from the central hole a to the periphery of the sheet Without stretching or weakening the sheet. By this method I can economically make corrugated disks for vehicle Wheels according to my patent previously mentioned, which have maximum rigidity and strength and are extremely light and durable.

Having thus described my invention what I claim and desire to secure by Letters Patent is- 1. The method of radially corrugating a sheet which consists in making a hole in the sheet at the axial center of the corrugations large enough to allow for radial shrinkage due to the corrugating process, forming guideways in'the sheet and then stamping the sheet to form the corrugations and simultaneously shrinking the sheet radially.

2. The method of radially corrugating a sheet which consists in making a hole in the sheet at the aXial center of the corrugations, forming guideways in the sheet and then striking out each corrugation separately with the corrugation extending the full radial depth of the sheet from the hole to the periphery of the sheet.

3. The method of radially corrugating a sheet, which consists in dividing the sheet into equal sectors, making guides in each of the sectors, and forming each corrugation singly and providing for shrinkage of the sheet lengthwise of the corrugations simultaneously with the making of each corrugation.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

ANDREW w. LIVINGSTON.

l/Vitnesses:

JOHN H. HERRING, BEATRICE ABRAMs. 

